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Permanently Attaching Muzzel Device

Discussion in 'Rifle Discussion' started by RedneckRampage, Jan 10, 2015.

  1. RedneckRampage

    RedneckRampage Newberg Well-Known Member

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    I have a question about permanently attaching a flash hider. I know the ideal way is to have the device installed, drilled, pinned, then the end of the pin welded. I also read that the ATF is on with just welding the device and not pinning it.

    I can MIG weld, and am wondering, will a small tack weld from the MIG welder hurt the barrel? Will this satisfy the ATF?

    I'm trying to save some money, gunsmiths that I ask, want a lot to pin and weld.
  2. IronMonster

    IronMonster Washington Opinionated Member Diamond Supporter

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    A pulse with a TIG machine would be much better. The problem with a MIG set up is that in order to get it to actually stick you will need quite a bit of voltage/amperage and you will heat a larger part of the barrel. But you can do it with a MIG. Drill you a little divot that is half on the barrel and half on the muzzle device for your weld to go (start with a strong center punch mark and drill with like a sharp 3/16 drill) Warm the spot up (with like a propane torch) to around 400 deg, no hotter or you will start to affect the heat treat of the barrel. Set the welder up hot. If your using .035 wire I would say something like 24V and 400 IPM wire speed. Make your spot weld and then put the entire thing in a blanket and leave it over night. You want it to cool slow. Under no circumstances do you want to cool it with a wet rag or dunk it in water. That will not only put things in stress but could dramatically change the heat treat in the barrel and could cause it crack at the weld (it would have to be pretty hot when you dunked it, but still just dont do it)

    If you where going to be in the Seattle area anytime I would TIG it for you. The reason being is you can get a super hot pulse that does not heat up much else but creates a nice clean fusion weld. Less chance of heat affecting the barrel or inflicting weird stress from shrinking metal.
    FA9 likes this.
  3. the4thshake

    the4thshake Portland Active Member

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    Send it to ADCO firearms. I believe they charge $30 to pin and weld. They did one for me a while back and I am pleased with their work.
  4. Nwcid

    Nwcid Yakima and N of Spokane Well-Known Member

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    I don't know anything about welding but here are the specific things the ATF says.


    The ATF procedure for measuring barrel length is to measure from the closed bolt (or breech-face) to the furthermost end of the barrel or permanently attached muzzle device. Permanent methods of attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver soldering, or blind pinning with the pin head welded over. Barrels are measured by inserting a dowel rod into the barrel until the rod stops against the bolt or breech-face. The rod is then marked at the furthermost end of the barrel or permanently attached muzzle device, withdrawn from the barrel, and measured.
  5. iamme

    iamme Lane County Well-Known Member

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    Weapon Outfitters is cheap and quick as well. Had one done and back in hands quickly. Worth having done right and not risking a barrel or FH.